Battery pack

Abstract

The present invention features a battery pack, that is provided to supply electricity to a variety of electric parts, such as a drive motor, installed in an environment friendly electric vehicle such as a fuel cell vehicle or a hybrid electric vehicle. Preferably, the battery pack is configured to stack cell assemblies. Each cell assembly includes a cell case. The cell case includes windows in opposite surfaces thereof such that unit cells are exposed, and recesses in opposite long lateral faces thereof such that the windows communicate with an outside. The windows and the recesses define cooling passages between the stacked cell assemblies.

1. A battery pack in which:
 cell assemblies are stacked; 
 each cell assembly includes a cell case; 
 each cell case includes windows in opposite surfaces thereof such that unit cells are exposed, and recesses in opposite long lateral faces thereof such that the windows communicate with an outside; and 
 the windows and the recesses define cooling passages between the stacked cell assemblies, 
 wherein each cell assembly comprises: 
 first and second cases each including the windows and recesses, and assembled so as to define an inner space; 
 unit cells received in the inner space defined by the first and second cases; and 
 wherein a fixing window member fixing the unit cells to inner surfaces of the first and second cases under pressure, and 
 the fixing window member comprises a frame structure with a window, is interposed between the unit cells in the inner space defined by the first and second cases, and fixes the unit cells to the first and second cases, and 
 exposes intermediate parts of the unit cells through the window thereof, is interposed between circumferences of the opposite unit cells, and fixes the circumferences of opposite unit cells to the inner surfaces of the first and second cases under pressure. 
 
     
     
       2. The battery pack of  claim 1 , wherein each cell case includes at least one stud and hole on outer surfaces thereof, which are contact surfaces of each cell assembly, and two neighboring cell assemblies are staked by fitting the stud into the hole. 
     
     
       3. The battery pack of  claim 1 , wherein the fixing window member
 is formed of a material having compressive deformability and elasticity, 
 is compressed by protrusions formed on the inner surfaces of the first and second cases when the first and second cases are assembled, and 
 fixes the circumferences of the opposite unit cells against and to the protrusions under pressure.